Special coatings

In
order that standard components can function for long periods, without
maintenance and reliably even under extreme operating conditions,
the Schaeffler Group has developed several coatings for such requirements.

These
coatings increase the corrosion╳Reaction of a metallic material with its environment. resistance and/or wear╳Undesirable change to dimensions and/or surfaces of materials due to frictional forces resistance of
the surface.

The
selection of the coating╳Surface technology to improve tribological behaviour, corrosion resistance, e.g. by INA Corrotect and for electrical insulation. is always dependent on the area of operation
and the application.

The
high hardness╳Resistance of a body to indentation by another body; hardness is either intrinsic or is achieved by heat treatment processes (steel) and/or thermochemical diffusion; for rolling bearings, hardness is measured in Rockwell (HRC) or Vickers (HV) of the thin film chromium plating╳Thermo-chemical corrosion protection in which the surface layer of a material is enriched with chromium by up to 35%. Used instead of corrosion resistant materials. and the special surface
structure give an anti-wear effect. The columnar structure has a
certain capacity for storage of lubricant. This ensures adequate lubricant
in the rolling element╳Point or rotationally symmetrical bodies for transmitting loads between raceways. contact zone even under extreme environmental
and operating conditions.

A
particularly high level of wear╳Undesirable change to dimensions and/or surfaces of materials due to frictional forces resistance together with a very high
anti-corrosion effect is achieved by the coating╳Surface technology to improve tribological behaviour, corrosion resistance, e.g. by INA Corrotect and for electrical insulation. Protect B, which
has an additional layer of chromium mixed oxide. Due to its
surface quality, this ensures separation of the contact between the
rolling element and hard chromium layer╳Chromium layer. Galvanic coating by electrolysis. and thus gives emergency
running characteristics and reduction of wear╳Undesirable change to dimensions and/or surfaces of materials due to frictional forces under extreme operating
conditions. Even under highly unfavourable environmental
conditions, this coating╳Surface technology to improve tribological behaviour, corrosion resistance, e.g. by INA Corrotect and for electrical insulation. still acts in a supportive capacity to
the lubricant. Since the coating╳Surface technology to improve tribological behaviour, corrosion resistance, e.g. by INA Corrotect and for electrical insulation. increases the wear╳Undesirable change to dimensions and/or surfaces of materials due to frictional forces resistance
of the base material, the preload╳Force due to negative operating clearance or negative bearing clearance in rolling bearings is maintained over an
extended period.

For use in the food
industry, compliance with exacting environmental and health conditions
must be achieved. The coating╳Surface technology to improve tribological behaviour, corrosion resistance, e.g. by INA Corrotect and for electrical insulation. Protect A is free from Cr(VI) and
can therefore be used in this sector.

Corrotect® special coating

Anti-corrosion protection

Corrotect® is
a surface coating╳Surface technology to improve tribological behaviour, corrosion resistance, e.g. by INA Corrotect and for electrical insulation. applied by electroplating, Figure 1. It is an extremely
thin anti-corrosion coating╳Surface technology to improve tribological behaviour, corrosion resistance, e.g. by INA Corrotect and for electrical insulation. with cathodic protection╳Coatings and layers on metallic materials to prevent damage from corrosion. and black chromate
passivation. Under load, it is compacted into the surface
roughness profile and partially worn away.

In
parts coated with Corrotect®, running-in occurs in the area of the
seal and an optically bright area develops as a result. Due
to the remote cathodic protection╳Coatings and layers on metallic materials to prevent damage from corrosion. mechanism, formation of rust╳Corrosion on iron and steel. in
this area can also be prevented.

does
not impair the load╳Load which, for example, is to be supported at a friction point. Also strain from pressure and/or heat.

See Contact surface carrying capacity, in contrast to the use of
corrosion-resistant steels

is
extremely resistant to corrosion

offers
protection against rust╳Corrosion on iron and steel. on all surfaces

ensures
rust protection╳Coatings and layers on metallic materials to prevent damage from corrosion. of smaller bright spots due to its cathodic protection
effect

gives
protection against EP additives

has
good thermal conductivity.

Application in the food industry

For
application in the food industry, the Schaeffler Group also offers the
special coating╳Surface technology to improve tribological behaviour, corrosion resistance, e.g. by INA Corrotect and for electrical insulation. Corrotect® in a Cr(VI)-free version, Figure 2.

The Cr(VI)-free special coating╳Surface technology to improve tribological behaviour, corrosion resistance, e.g. by INA Corrotect and for electrical insulation. Corrotect® fulfils the RoHS requirements in accordance with EU Guideline 2002/95/EG. All other advantages are identical with the standard Corrotect® coating, see page link.

Applications

Components
coated with Corrotect® are particularly suitable where corrosion
resistance is the most important factor.

The
coating is also used very successfully to prevent adhesion╳Binding force of a body to another body, e.g. a lubricant to a surface of weld
spray.

Available products

The following products
in the field of linear motion are available with the Corrotect® coating:

Components with the Corrotect®coating╳Surface technology to improve tribological behaviour, corrosion resistance, e.g. by INA Corrotect and for electrical insulation. containing Cr(VI) have the suffix RRF; components with the Corrotect®coating╳Surface technology to improve tribological behaviour, corrosion resistance, e.g. by INA Corrotect and for electrical insulation. free from Cr(VI) have the suffix RROC; see Ordering designation.

Ordering designation

The
ordering designation╳Identification of a bearing by letters and numbers, indicating, for example, the series, dimensional series or size code, bore diameter, bearing design and information such as Corrotect plating or length of guideways for a recirculating ball guidance system KUVE25-B with two carriages, accuracy G3 and preload class V1 and
the Corrotect®coating╳Surface technology to improve tribological behaviour, corrosion resistance, e.g. by INA Corrotect and for electrical insulation. containing Cr(VI) is:

KUVE25-B-W2-G3-V1-RRF/

The
ordering designation╳Identification of a bearing by letters and numbers, indicating, for example, the series, dimensional series or size code, bore diameter, bearing design and information such as Corrotect plating or length of guideways for a recirculating ball guidance system KUVE45-B-KT with one carriage, accuracy G2 and preload class V1 and
the Corrotect®coating╳Surface technology to improve tribological behaviour, corrosion resistance, e.g. by INA Corrotect and for electrical insulation. free from Cr(VI) is:

KUVE45-B-KT-W1-G2-V1-RROC/

Technical/physical datafor Corrotect®

The
table shows technical/physical data for the special coating╳Surface technology to improve tribological behaviour, corrosion resistance, e.g. by INA Corrotect and for electrical insulation. Corrotect®.

Table 1Corrotect® data

Characteristics

Containing Cr(VI)

Free from Cr(VI)

Suffix

RRF

RROC

Colour

Black

Colourless, blue to iridescent

Thickness1)

0,5 μm – 3 μm

0,5 μm – 3 μm

Number of layers

1

1

Composition

Zinc alloyed with iron and cobalt

Zinc alloyed with iron

Hardness

300 HV

300 HV

Anti-corrosion protection2)

96 h

96 h

Anti-wear protection

-

-

Maximum single-piece length

3 500 mm

3 500 mm

Free from Cr(VI)3)

No

Yes

Close window

Characteristics

Containing Cr(VI)

Free from Cr(VI)

Suffix

RRF

RROC

Colour

Black

Colourless, blue to iridescent

Thickness1)

0,5 μm – 3 μm

0,5 μm – 3 μm

Number of layers

1

1

Composition

Zinc alloyed with iron and cobalt

Zinc alloyed with iron

Hardness

300 HV

300 HV

Anti-corrosion protection2)

96 h

96 h

Anti-wear protection

-

-

Maximum single-piece length

3 500 mm

3 500 mm

Free from Cr(VI)3)

No

Yes

______

1

Thickness in functional
area.

2

Salt spray test to DIN 50 021.

3

Parts containing Cr(VI)
are not suitable for the food industry.

Protect A

Anti-wearand anti-corrosion protection

Protect A
is a pure chromium layer╳Chromium layer. Galvanic coating by electrolysis. with a columnar surface structure, Figure 3.

The
coating is applied by electroplating. The parts to be coated are
heated to approx. +50 °C.
Since no structural changes occur, the parts retain full dimensional
stability.

The
matt grey chromium layer╳Chromium layer. Galvanic coating by electrolysis. retains a certain amount of lubricant╳Gaseous, fluid, consistent, plastic or solid material for reduction of friction and wear between two friction elements. between
the pearls. As a result, effective anti-wear protection╳Coatings and layers on metallic materials to prevent damage from corrosion. is
achieved even under mixed friction╳Friction condition where the lubricant film is not complete and the surface peaks of the friction partners may still come into contact or slippage conditions.

Operating temperature

The
temperature range of the guidance system is between –10 °C and +100 °C.

Figure 3Thin film chromium platingProtect A

KUVE..-B-KD

Advantages

The
coating:

is
resistant to various chlorides, various oils, sulphur
compounds, chlorine compounds and weak acidic media

does
not influence the load╳Load which, for example, is to be supported at a friction point. Also strain from pressure and/or heat.

has
higher wear╳Undesirable change to dimensions and/or surfaces of materials due to frictional forces resistance due to its high hardness

ensures
effective anti-wear protection╳Coatings and layers on metallic materials to prevent damage from corrosion. even under mixed friction╳Friction condition where the lubricant film is not complete and the surface peaks of the friction partners may still come into contact conditions

offers
good protection╳Coatings and layers on metallic materials to prevent damage from corrosion. against EP additives

has
good thermal conductivity

is
moderately resistant to corrosion

prevents
false brinelling under vibration while stationary

is
free from Cr(VI).

Applications

Protect A
does not contain Cr(VI). Components with this coating╳Surface technology to improve tribological behaviour, corrosion resistance, e.g. by INA Corrotect and for electrical insulation. are therefore
particularly suitable for use in the food industry, medical
equipment and similar areas.

The
coating is recommended for use under particularly small stroke lengths
and vibration while stationary.

Available products

The
following products in the field of linear motion are available coated
with Protect A:

Other
products in the shaft and track roller range are available by agreement
with the Protect A coating.

Suffixes

Components coated with Protect A have the suffix KD; see Ordering designation.

Ordering designation

The
ordering designation╳Identification of a bearing by letters and numbers, indicating, for example, the series, dimensional series or size code, bore diameter, bearing design and information such as Corrotect plating or length of guideways for a Protect A-coated recirculating ball guidance system KUVE25-B with two carriages, accuracy G3 and preload class V1 is:

KUVE25-B-W2-G3-V1-KD/

Technical/physical datafor Protect A

The
table shows technical/physical data for the special coating╳Surface technology to improve tribological behaviour, corrosion resistance, e.g. by INA Corrotect and for electrical insulation. Protect A.

Table 2Protect A data

Data

Suffix

KD

Colour

Matt grey

Thickness1)

0,5 μm – 4 μm

Number of layers

1

Composition

Pure chromium layer
with pearly
surface

Hardness

900 HV – 1 300 HV

Anti-corrosion protection2)

8 h

Anti-wear protection

Under mixed friction

Maximum single-piece
length

4 000 mm

Free from Cr(VI)3)

Yes

Close window

Data

Suffix

KD

Colour

Matt grey

Thickness1)

0,5 μm – 4 μm

Number of layers

1

Composition

Pure chromium layer
with pearly
surface

Hardness

900 HV – 1 300 HV

Anti-corrosion protection2)

8 h

Anti-wear protection

Under mixed friction

Maximum single-piece
length

4 000 mm

Free from Cr(VI)3)

Yes

______

1

Thickness in functional
area.

2

Salt spray test to DIN 50 021.

3

Parts free from Cr(VI)
are suitable for the food industry.

When using Protect A,
coated carriages and coated guideways must always be combined. If
coated carriages are used with uncoated guideways, for example,
this will lead to a reduction in preload.

Protect B

High anti-corrosion and anti-wear protection

Protect B
comprises two layers: a thin film chromium plating╳Thermo-chemical corrosion protection in which the surface layer of a material is enriched with chromium by up to 35%. Used instead of corrosion resistant materials. (Protect A)
is covered by chromium
mixed oxide, Figure 4.

The
corrosion resistance is provided by the chromium mixed oxide layer.
This layer acts in a supportive capacity to the lubricant╳Gaseous, fluid, consistent, plastic or solid material for reduction of friction and wear between two friction elements. when used
in aggressive atmospheres and at high temperatures.

The
temperature range of the guidance system is between –10 °C and +100 °C.

Figure 4Thin film chromium platingProtect B

KUVE..-B-KDC

Advantages

The
coating:

is
resistant to various chlorides, various oils, sulphur compounds,
chlorine compounds and weak acidic media

does
not influence the load╳Load which, for example, is to be supported at a friction point. Also strain from pressure and/or heat.

offers
good protection╳Coatings and layers on metallic materials to prevent damage from corrosion. against EP additives

acts
in a supportive capacity to the lubricant╳Gaseous, fluid, consistent, plastic or solid material for reduction of friction and wear between two friction elements. by mean of the
second layer in aggressive atmospheres and at high temperatures

has
good thermal conductivity

offers
high anti-wear protection╳Coatings and layers on metallic materials to prevent damage from corrosion. together with high anti-corrosion protection

prevents
false brinelling under vibration while stationary.

Applications

Where
high requirements for anti-corrosion protection╳Coatings and layers on metallic materials to prevent damage from corrosion. are present and
continuous lubrication╳Feed of fresh lubricant to friction points. Fresh lubricant mixes with used lubricant at the friction point. Lubricant feed is by means of lubrication equipment. The time period for relubrication is shorter than that for the lubricant change interval.

Other
products in the shaft and track roller range are available by agreement.

Suffixes

Components coated with Protect B have the suffix╳Addition to the designation, consisting of letters and/or numbers, for example, it may indicate variants of a seriesKDC; see Ordering designation.

Ordering designation

The
ordering designation╳Identification of a bearing by letters and numbers, indicating, for example, the series, dimensional series or size code, bore diameter, bearing design and information such as Corrotect plating or length of guideways for a Protect B-coated recirculating ball guidance system KUVE25-B with two carriages, accuracy G3 and preload class V1 is:

KUVE25-B-W2-G3-V1-KDC/

Technical/physical datafor Protect B

The
table shows technical/physical data for the special coating╳Surface technology to improve tribological behaviour, corrosion resistance, e.g. by INA Corrotect and for electrical insulation. Protect B.

Table 3Protect B data

Data

Suffix

KDC

Colour

Black

Thickness1)

0,5 μm – 5 μm

Number of layers

2

Composition

Thin film chromium plating╳Thermo-chemical corrosion protection in which the surface layer of a material is enriched with chromium by up to 35%. Used instead of corrosion resistant materials. (Protect A) with coating╳Surface technology to improve tribological behaviour, corrosion resistance, e.g. by INA Corrotect and for electrical insulation. of chromium mixed oxide

Hardness

950 HV

Anti-corrosion protection2)

96 h

Anti-wear protection

Under inadequate lubrication

Maximum single-piece length

4 000 mm

Free from Cr(VI)3)

No

Close window

Data

Suffix

KDC

Colour

Black

Thickness1)

0,5 μm – 5 μm

Number of layers

2

Composition

Thin film chromium plating╳Thermo-chemical corrosion protection in which the surface layer of a material is enriched with chromium by up to 35%. Used instead of corrosion resistant materials. (Protect A) with coating╳Surface technology to improve tribological behaviour, corrosion resistance, e.g. by INA Corrotect and for electrical insulation. of chromium mixed oxide

Hardness

950 HV

Anti-corrosion protection2)

96 h

Anti-wear protection

Under inadequate lubrication

Maximum single-piece length

4 000 mm

Free from Cr(VI)3)

No

______

1

Thickness in functional
area.

2

Salt spray test to DIN 50 021.

3

Parts containing Cr(VI)
are not suitable for the food industry.

When using Protect B,
coated carriages and coated guideways must always be combined. If
coated carriages are used with uncoated guideways, for example,
this will lead to a reduction in preload.